Animal feed compositions and methods of using the same

ABSTRACT

Immune function of an animal can be modulated by administration of a composition that includes beta glucan. The beta glucan can be derived from Euglena, which provides a form of beta glucan that is different from other organisms, where the beta glucan is predominantly unbranched beta-(1,3)-glucan. Beta glucan can also be complexed with a metal, such as zinc, and/or can combined with an animal feed component to form an animal feed composition. Use of such compositions can improve the well being of an animal, and may augment or even replace the use of antibiotics in certain circumstances.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.13/773,971, filed Feb. 22, 2013, entitled ANIMAL FEED COMPOSITIONS ANDMETHODS OF USING THE SAME, which claims the benefit of U.S. ProvisionalApplication No. 61/601,891, filed on Feb. 22, 2012. The entiredisclosures of which are hereby incorporated by reference in theirentireties.

FIELD

The present technology relates to beta glucan, trace metals, andcomplexes of beta glucan and trace metals, and uses thereof to modulateimmune function, including providing such compositions as oralsupplements or admixed with animal feed.

INTRODUCTION

This section provides background information related to the presentdisclosure which is not necessarily prior art.

Animals are exposed to many stresses during their lives that have beenshown to affect health, growth, mortality, immune system health, andoverall well-being of the animal. Currently, antibiotics and othertreatments are used to improve the ability of an animal to resistdisease and as treatment for a disease. An over-dependence uponantibiotics in modern agriculture and human health has led to widespreadantibiotic resistance and led to a desire for more natural ways topromote healthy immune function.

Natural alternatives to antibiotics could be used to combat infectiousdiseases. Currently, infectious diseases are a leading cause ofmortality in the world. In the United States, only cancer and heartdisease lead to more deaths in humans than infectious diseases.Antibiotics are often necessary to treat infectious diseases in humansand animals. However, when antibiotics are used continuously, resistantbacterial strains can evolve. Such antibiotic resistance is a serioushuman health problem and has contributed to increased deaths fromantibiotic-resistant bacterial strains like methicillin-resistantStaphylococcus aureus (MRSA). For example, antibiotic-resistant strainsof bacteria are now cited as the cause of more deaths in the UnitedStates than HIV/AIDS.

Despite the need to preserve the integrity of antibiotics for humanapplications, usage of antibiotics in animal applications comprises over80% of the total antibiotic use in the United States. From 1985 to 2003,sub-therapeutic usage of antibiotics in animal feed applications hasgrown tenfold. Development of a non-antibiotic animal feed ingredientthat promotes immune system health could help reduce the prevalence ofantibiotic-resistant bacterial strains that are also harmful to humanbeings. Such an ingredient may be more beneficial when used in livestockgrowth conditions that are antibiotic free. Several nations other thanthe U.S. do not permit the sub-therapeutic use of antibiotics in animalfeed, and may even prohibit the imp0liation of meat products grown usingantibiotics from the U.S. In order to be commercially effective, such aningredient must be cost effective, reliable, safe, and able to beincluded into the existing water or feed infrastructure.

An example of a compound used to stimulate immune system activity isbeta glucan. Beta glucans are polysaccharides connected by betaglycosidic linkages that can be found in various organisms, such asyeast, mushrooms, fungi, cereal grains, and others. Beta-glucan is usedas a dietary supplement and various beneficial effects thereof are thesubject of various clinical trials. Beta glucan products are currentlyderived primarily from yeast, where they are extracted from the yeastcell wall using various processes. Examples of these products andprocesses are described in U.S. Pat. Nos. 5,082,936; 5,633,369;6,444,448; 7,981,447; and U.S. Pub. Nos. 2008/0108114; and 2004/0082539.Other beta glucan products exist, including ones derived from mushrooms,oats, barley, and kelp. Although these products demonstrate beneficialeffects in some cases, these beta glucan products are generallyconsidered to be too expensive for a majority of animal feedapplications. The most effective beta glucans produced using thesemeans, for example, were commercially valued between about 50 to 100 USDper kg of beta glucan in 2011, a price that is prohibitive to themajority of people and animal producers.

One reason for the high cost is that the beta glucans in these productsare derived from the cell wall of the organism. As such, the resultingbeta glucan content of the total biomass used to produce the beta glucanis generally less than ten to fifteen percent. Moreover, the betaglucans contained in an organism's cell wall generally must undergoexpensive, multi-stage extraction processes in order to separate thebeta glucan from other cellular materials.

Beta glucan structure is also complex. Variations in branchingstructure, molecular weight, source organism, and method of productionand extraction can all affect the efficacy and suitability of differentbeta glucan products. For example, yeast-derived beta-1,3;1,6-glucanscomprise the majority of commercial beta glucan products that areintended to stimulate immune system activity. Beta-1,3:1,4-glucans fromoats have been demonstrated as useful for reducing cholesterol, and onlythese types of beta glucans may be labeled as such according to FDAregulations. Many organisms produce different beta glucan structures,and all beta glucans are not equally effective. Although there isresearch on the usefulness or efficacy of beta glucans derived fromyeast (e.g., U.S. Pat. No 6,939,864), mushrooms, or oats (e.g., U.S.Pub. No. 2011/0123677), there is less research on beta glucans derivedfrom algae or protist-derived sources. Moreover, algae and protists arenot produced in commercial quantities that are beneficial for their betaglucan content.

Beta glucans produced by different organisms and extracted withdifferent techniques may have very different effects when fed to animalsas a component of an animal feed composition, and this may also affectdosing of the beta glucan. In the document, “Effects of beta-glucanextracted from Saccharomyces cerevisiae on growth performance, andimmunological and somatotropic responses of pigs challenged withEscherichia coli lipopolysaccharide,” published in the Journal of AnimalScience, Li et al. wrote, “[t]he results of current study indicate thatthe addition of β-glucan to weaned pig diets is able to offer somebenefits on growth performance and immune response to alipopolysaccharide challenge. However, β-glucans produced by differentproduction methods may have different effects on growth performance andimmune function in weaned piglets. Source of β-glucan produced bydifferent methods may vary in their structure, chemical composition, orboth, which may influence its activity and the amount that should beadded to get a growth response. Therefore, further investigation iswarranted to better discern the performance and immune response ofβ-glucan produced by different methods when it is supplemented to swinediets.”

Although beta glucans produced by an algae or a protist such as Euglenagracilis may be similar to beta glucans from other sources, these betaglucans are also unique in several ways. For example, the dissimilarevolutionary history that algae and protists have when compared tofungi, plants, or bacteria leads them to produce hundreds of uniquecompounds, some of which may act as yet-to-determine co-factors to betaglucan. The use of algae or protist-derived beta glucans as anutritional food and feed supplement may provide lower-cost andpotentially higher purity immune modulating supplements for human andanimal food supplement applications. In addition, inclusion of betaglucans in the form of an algae or protist meal or supplement wouldremove the need for potentially harmful or expensive solvent-basedextraction-processes, such as the processes that are used to extractbeta glucans from the cell walls of yeast or mushrooms, and may permitthe inclusion of additional co-factors and nutrients which are suppliedby the algae or protist, such as Vitamin E, zinc, Omega 3 fatty acids,and other known or unknown nutritionally beneficial molecules.

In addition to the beneficial immunological aspects relating tobeta-glucan, the presence in animal freed of certain trace metals insufficient quantities, and in biologically available forms, is importantfor maintaining the well-being of animals. Because essential tracemetals are often deficient in commodity feed ingredients, supplementalamounts of these nutrients are often added to feed.

Trace metals have also been shown to effect general immune systemperformance. Inorganic salts such as zinc oxide and zinc sulfate areoften provided as a trace mineral supplement. However, there can beincomplete absorption of these inorganic sources. The p01iion of thetrace metal that is not absorbed is likely to pass through an animal'sdigestive tract into the feces, where it may accumulate. For example,animal waste that is laden with very high concentrations of zinc may beconsidered to be toxic, with trace metal accumulation causingenvironmental damage if the animal waste is spread excessively on fieldsas a fertilizer source, as is a common practice.

Many commercial products exist in which the bioavailability of traceelements is increased compared to an inorganic source of the same metal.The increased bioavailability can be due the association of an organicmolecule, which can be a protein, amino acid, or polysaccharide, wherethe organic molecule is generally termed a ligand. There are differentexplanations for why organically bound trace metals have increasedbioavailability. One explanation is that binding to an organic moleculeprovides greater stability in the gut, reducing the probability that astronger agonist that would prevent absorption into the body binds thetrace metal. Another explanation is that the organic metal complex isabsorbed together through the lining of the intestine. Table 1summarizes some examples of classifications of trace metal and ligandproducts.

TABLE 1 Examples of Organic Metal Complexes. Description Examples (U.S.Pat. Nos. unless otherwise noted) metal proteinate 3,440,054; 3,463,858;3,775,132; 3,969,540; 4,020,158; 4,076,803; 4,103,003; 4,172,072;5,698,724 metal amino acid 3,941,818; 3,950,372; 4,067,994; 4,863,898;4,900,561; 4,948,594; complex or chelate 4,956,188; 5,061,815;5,278,329; 5,583,243; 6,166,071; 3,950,372; 4,021,569; 4,039,681;4,067,994; 5,278,329; 4,900,561; 4,948,594; 4,956,188; 5,583,243;7,129,375 metal propionate 5,591,878; 5,707,679; 5,795,615; 5,846,581metal 8,273,393; 4,661,358; EP 0712581 polysaccharide complex

FIG. 1 provides visual representations of these various organic metalcomplexes. Different types of products containing trace elementsassociated with an organic ligand can further be classified intodifferent groups based on the ligand used in producing the product.

It is desirable to find ways to improve the effectiveness of an animal'simmune system against infectious diseases without relying onantibiotics.

SUMMARY

The present technology includes systems, processes, articles ofmanufacture, and compositions that relate to modulating immune systemfunction by administering a beta glucan to an animal. For example, thebeta glucan can be derived from Euglena, can be complexed with a tracemetal, and/or can be part of animal feed. The well being of an animalcan be improved through the administration of beta glucan, where “wellbeing” includes enhancement in one or more of the following aspects:weight gain, conversion efficiency of food to live weight, behavior,disease resistance, stress tolerance, reduced mortality rates, andimproved immune function. The source of beta glucan can be a non-toxic,non-pathogenic algae or protist of the genus Euglena.

In certain aspects, a method of modulating the immune function of ananimal is provided where the method includes administering to the animala composition comprising beta glucan, the beta glucan comprising linear,unbranched, beta-(1,3)-glucan. The beta glucan can be derived fromEuglena and can be derived from heterotrophically grown Euglena. Thebeta glucan can also consist essentially of unbranched beta-(1,3)-glucanand can have an average molecular weight of about 200-500 kDa. The betaglucan can also have greater than about 90% unbranchedbeta-(1,3)-glucan. The beta glucan can be in the native form ofparamylon, which is a water insoluble granule, or can be water soluble.The composition can include algae meal, where the algae meal includesthe beta glucan. The composition can further include a metal, such asiron, magnesium, lithium, zinc, copper, chromium, nickel, cobalt,vanadium, molybdenum, manganese, selenium, iodine, and combinationsthereof. The beta glucan and the metal can form a complex and in aceltain embodiment comprises a zinc beta glucan complex. Administeringthe composition can include adding the composition to the animal's dietor drinking water. The composition can also include an animal feedcomponent.

In various aspects, an animal feed composition is provided that includesa linear, unbranched beta-(1,3)-glucan and an animal feed component.

In some aspects, a composition is provided that includes a complex of ametal and a beta glucan.

The present technology demonstrates that beta glucans can be produced ata low cost by using an algae or protist such as Euglena sp. usingcontrolled growth methods. The structure of these beta glucans isdifferent from the beta glucans produced using other organisms. Onemajor difference is that while other organisms produce beta glucansincorporated into their cell wall, the genus of protists known asEuglena can produce beta glucan, including a particulate form of betaglucan, known as paramylon, that is not incorporated into the structureof the cell wall. Rather, Euglena accumulates beta glucan as awater-insoluble granule in the cytoplasm and utilizes this form of betaglucan as a form of carbohydrate energy storage,

Under optimized growth conditions, it is possible to achieveconcentrations of beta glucan where the net beta glucan weight isgreater than 20% to 80% of the total dry weight proportion of thebiomass. Achieving these levels of production efficiency can becomplicated by the fact that growth of the Euglena is achieved inselective conditions that compensate for the faster growth rates ofyeast, fungi, and other microorganisms that may be competing for thesame carbon source as the Euglena. The present technology provides meansto maximize Euglena growth while minimizing competing microorganismgrowth. The beta glucan compounds produced by Euglena are not the sameas other products that are produced using yeast and other organisms, butthe beta glucans from Euglena are effective at improving immunefunction. A further benefit is that beta glucan production cost can beless than ½ to ⅕ the production cost of beta glucans that are producedusing yeast.

In other embodiments, the present technology includes a compositioncomprising an effective amount of beta glucan produced by an algae orprotist such as Euglena, where the composition is used to improve thewell-being of an animal. Lower-cost beta glucan feed additives producedusing algae therefore provide affordable and natural alternatives toantibiotics and other immune-improving substances for use in animalsthat can benefit animal husbandry, aquaculture, and even human healthapplications.

Further areas of applicability will become apparent from the descriptionprovided herein. The description and specific examples in this summaryare intended for purposes of illustration only and are not intended tolimit the scope of the present disclosure.

DRAWINGS

The drawings described herein are for illustrative purposes only ofselected embodiments and not all possible implementations, and are notintended to limit the scope of the present disclosure.

FIG. 1A depicts a representation of an organic metal complex for a metalpolysaccharide complex.

FIG. 1B depicts a representation of an organic metal complex for a metalproteinate complex.

FIG. 1C depicts a representation of organic metalcomplex for a metalamino acid complex.

FIG. 1D depicts a representation of an organic metal complex for a metalpropionate complex.

FIG. 1E depicts a representation of an organic metal complex for a metalamino acid chelate.

FIG. 2 depicts a beta-1,3 glucan chain with other branching locationsindicated. Paramylon, a form of beta glucan from Euglena, is unique inthat it consists almost entirely of linear, beta-1,3-branches.

FIG. 3 illustrates a yeast cell wall containing beta glucan that isembedded into the cell wall. Unlike in Euglena gracilis, extraction andseparation processes are necessary to make the beta-1,3;1,6-glucan fromyeast fully bioavailable to immune cell receptors.

FIGS. 4A-D illustrate the linkage differences between beta glucanbranching structures based on the source of the beta glucan, where FIG.4A illustrates Euglena produce beta-1,3 glucans called “Paramylon.”

FIG. 4B illustrates yeast-derived products consist ofbeta-1,3;1,6-branches that are extracted from the cell walls of yeast.

FIG. 4C illustrates beta-1,3;1,4-glucans are more commonly derived fromoats or barely and have been demonstrated to reduce cholesterol.

FIG. 4D illustrates Laminaria produce side-chain branchedbeta-1,3;6-glucans.

FIG. 5 is a schematic of an embodiment of a fermentation processaccording to the present technology.

FIG. 6 is a schematic of another embodiment of a fermentation processaccording to the present technology.

FIG. 7 graphically depicts the mass in dry weight per liter of Euglenaand beta glucan grown in a control media and a media having a supplementcarbon treatment.

FIG. 8 graphically depicts the percent beta glucan by dry weight ofEuglena grown in the control media and the media having the supplementalcarbon treatment.

FIG. 9 graphically depicts the phagocytosis index of mouse neutrophilssampled from peripheral blood 48 hours after being fed heterotrophicallygrown paramylon. Commercial yeast beta glucan products, i.e., Fibosel(Trouw Nutrition, Highland, Ill.) and Macrogard (Orffa Inc., Henderson,Nev.), were compared to dried heterotrophically-produced Euglena cells(WBG50) and paramylon extracted from said cells. Bars represent means(±SE), (n=3 mice).

FIG. 10 graphically depicts natural killer (NK) cell activity of spleencells harvested 48 hours after being fed heterotrophically grownparamylon. Commercial yeast beta glucan products (Fibosel, Macrogard)were compared to dried heterotrophically-produced Euglena cells (WBG50)and paramylon extracted from the cells. Bars represent means (±SE), (n=3mice).

FIG. 11 graphically depicts IL-2 (cytokine) formation (by ELISA) in mice48 hours after being fed heterotrophically grown paramylon. Commercialyeast beta glucan products (Fibosel, Macrogard) were compared to driedheterotrophically-produced Euglena cells (WBG50) and paramylon extractedfrom said cells. Bars represent means (±SE), (n=3 mice)

FIG. 12 graphically depicts antibody formation following ovalbumininjection and daily dosing of heterotrophically grown paramylon.Commercial yeast beta glucan products (Fibosel, Macrogard) were comparedto dried heterotrophically-produced , Euglena cells (WBG50) andparamylon extracted from said cells. Bars represent means (±SE), (n=3mice).

FIG. 13 graphically depicts survivorship of mice following an injectionof E. coli on day 0. Algae meal, purified algae beta glucan, andMacrogard yeast beta glucan extract were fed orally by gavage for 5 daysat a dose equivalent to 0.01% of the daily feed ration starting 2 daysbefore the E. coli injection (day—2). The PBS control group was givenjust a PBS gavage while the antibiotic treatment group was given 13mg/kg of Ampicillin orally on days 0 through 4. (n=10 mice per treatmentgroup).

FIG. 14 graphically depicts antibody formation following ovalbumininjection (day 3 and 16) and daily dosing of beta glucan treatments for23 days. Bars represent means±standard error. n=3 mice per treatmentgroup.

FIG. 15 graphically depicts Natural Killer (NK) cell activity of spleencells harvested on day 14. Bars represent means±standard error. n=3 miceper treatment group.

FIG. 16 graphically depicts the phagocytosis index of mouse neutrophilssampled from peripheral blood on day 14. Bars represent means±standarderror. n=3 mice per treatment group.

DETAILED DESCRIPTION

The following description of technology is merely exemplary in nature ofthe subject matter, manufacture and use of one or more inventions, andis not intended to limit the scope, application, or uses of any specificinvention claimed in this application or in such other applications asmay be filed claiming priority to this application, or patents issuingtherefrom, Regarding the methods disclosed, the order of the stepspresented is exemplary in nature, and thus, the order of the steps canbe different in various embodiments. Except in the examples, or whereotherwise expressly indicated, all numerical quantities in thisdescription indicating amounts of material or conditions of reactionand/or use are to be understood as modified by the word “about” indescribing the broadest scope of the technology.

The present technology relates to beta glucan, including beta glucanderived from Euglena, and uses thereof. Compositions containing Euglenaderived linear beta-1,3-glucan can be orally administered to promoteimmune system health, prevent disease, reduce mortality, reduce theeffects of stress, increase growth rates, or improve feed conversionefficiency in animals. Various commercially raised animals, such asmammals, fish, birds, and crustaceans, can be treated. Dosages or feedinclusion rates can vary depending upon the animal species that isadministered the beta glucan. In certain embodiments, thebeta-1,3-glucan can comprise less than 1% of the total feed. Animals canalso be treated at any stage of life, although animals that are raisedfor the purpose of breeding are often considered to be more valuable andtherefore it may be considered to be more economical to treat theseanimals. The present technology is intended to include compositions, useof the compositions, and various methods as described herein to enhancethe well-being of animals. Methods used to prepare such compositions arealso included in the present technology.

Carbohydrate Branching Structure

With reference to FIGS. 2, 3, and 4, aspects of various beta glucansfrom various sources are shown. The beta glucan produced by Euglenoidsis unique in its physical characteristics and is often referred to as“paramylon.” Paramylon consists of a linear polymer that is almostexclusively beta-1,3 glucan with very few side branches. This structurediffers significantly from the yeast-derived beta glucans that have beenstudied most intensively and commercialized for immune supportapplications, Yeast beta glucans contain a beta-1,3 glucan backbone thatis substituted with beta-1,6 side chains (2-3 glucose units long) every10-30 glucose units. The unbranched nature of paramylon is an importantdistinction compared to other sources of beta glucans when consideringits use in immune support applications,

After isolating paramylon from whole Euglena cells, a linkage analysiswas performed to determine the relative amounts of each type of bondbetween glucose monomers. For glycosyl linkage analysis, the sample waspermethylated, depolymerized, reduced, and acetylated; and the resultingpartially methylated alditol acetates (PMAAs) were analyzed by gaschromatography-mass spectrometry (GC-MS) as described by York et al.(1985) Methods Enzymol. 118:3-40. Initially, dry sample was suspended inabout 300 μl of dimethyl sulfoxide and placed on a magnetic stirrer for1-2 weeks. The sample was then permethylated by the method of Ciukanuand Kerek (1984) Carbohydr. Res. 131:209-217 (treatment with sodiumhydroxide and methyl iodide in dry DMSO). The sample was subjected tothe NaOH base for 10 minutes then methyl iodide was added and left for40 minutes. The base was then added for 10 minutes and finally moremethyl iodide was added for 40 minutes. This addition of more methyliodide and. NaOH base was to insure complete methylation of the polymer.Following sample workup, the permethylated material was hydrolyzed using2 M trifluoroacetic acid (2 h in sealed tube at 121 C), reduced withNaBD4, and acetylated using acetic anhydride/trifluoroacetic acid. Theresulting PMAAs were analyzed on a Hewlett Packard 5975C GC interfacedto a 7890A MSD (mass selective detector, electron impact ionizationmode); separation was performed on a 30 m Supelco 2330 bonded phasefused silica capillary column.

TABLE 2 Linkage Analysis of 2 Paramlyon Samples Extracted from Euglenagracilis. GLYCOSYL RESIDUE Sample 1 Sample 2 terminally-linkedglucopyranosyl residue (t-glc) 0.34 0.3 3-linked glucopyranosyl residue(3-glc) 93.03 94.1 4-linked glucopyranosyl residue (4-glc) 2.25 2.42,3-linked glucopyranosyl residue (2,3-glc) 3.47 2.3 3,6-linkedglucopyranosyl residue (3,6-glc) 0.36 0.8 2,3,4-linked glucopyranosylresidue (2,3,4-glc) 0.55 0.1 Total 100.0 100.0

This linkage analysis indicates that both paramylon samples are mainlycomposed of 3-linked glucopyranosyl residues. For example, the betaglucan can be greater than about 90% unbranched beta-(1,3)-glucan, andin some cases can be greater than about 93% unbranched beta-(1,3)-glucanor greater than about 94% unbranched beta-(1,3)-glucan. Minor amounts of4-linked and 2,3 linked glucopyranosyl residues were found along withnegligible amounts of 3,6-linked, terminal and 2,3,4-linkedglucopyranosyl residues. These data confirm that paramylon is comprisedmostly of a linear, unbranched beta 1,3 glucan. According to severalstudies, beta-1,3 glucan is the form of beta glucan that actually bindsto receptors on the surface of immune system cells, such as Dectin-1 (amajor receptor on immune system cells like macrophages) and complementreceptor 3. Following the uptake of particulate paramylon and itsdigestion into smaller fragment by macrophages, the high proportionofbeta-1,3 glucan in paramylon relative to yeast-derived beta glucansmay result in improved immune system modulation. For example, immunesystem activation may be improved with increasing doses of paramylonwhereas efficacy may diminish with higher doses of yeast-based betaglucans, possibly due to the presence of beta-1,6 side chains thatstereometrically interfere with one another and hinder access to theDectin-1 receptor.

Three-Dimensional Structure

The three-dimensional structure and folding ofbeta-1,3-glucan can affectthe bioavailability, surface area, and overall efficacy in immunestimulation applications. In linear, beta-1,3-glucan chains, thestructure is governed by the glycosidic linkage pattern. Because thechair-form ring of glucopyranosyl is rather rigid, most of theflexibility of the glucan chain arises from rotations around the bondsof the glycosidic linkages. X-ray crystallography and spectroscopytechniques indicate that linear glucans have a triple-helix backbone inthe solid state. Paramylon that is produced by Euglena is considered tobe one of the structurally most simple of the beta glucans, with fewglycosyl side chains, This is in direct contrast to laminaran, lentinan,scleroglucan, schizopylann and yeast-derived beta glucans that have 1,4or 1,6-linked side chains exposed toward the exterior of the helicalstructure.

The triple-helix structure of linear beta-1,3-glucan is stabilized byree types of hydrogen bonding:

-   -   1. Intermolecular hydrogen bonding formed between the different        chains in the same x-y plane;    -   2. Intramolecular hydrogen bonding formed between adjacent O        atoms in the same chain; and    -   3. Intermolecular hydrogen bonding formed between different        chains in a different x-y plane.

The triple helix structure is stable over a broad range of temperaturesat a neutral pH, resulting in a polymer that is water insoluble.However, the hydrogen bonds can be destabilized by various means tochange the conformation of the paramylon polymer. For example, paramyloncan be dissolved in alkaline solutions (typically 0.2 M NaOH orstronger), aprotic polar solvents like DMSO, in the presence of strongchaotropic agents (e.g., urea), or by increasing temperatures above thetriple-helix melting temperatures (˜135 ° C.). Different immunologicaleffects can be obtained that are related to the beta-1,3-glucanconformation, be it the native state, denatured, or denatured andre-natured. Beta-1,3-glucan in any of these three conformations canserve as the building block for additional reactions that add or improveits functionality. Several of these modifications to producefunctionalized beta-1,3-glucans and some of their respectiveapplications are discussed herein. The conformation of the beta glucanand its resulting solubility may also affect how it is delivered; forexample, water soluble beta-1,3-glucan can be directly injected whereasparticulate beta glucan is more suitable for oral administration.

Particle Size, Molecular Weight, and Surface Area

The particle size, molecular weight, and surface are all factors thataffect the function and bioavailability of the beta-1,3-glucan particle,In general, it can be preferable to have a beta-1,3-glucan particlebetween 0.2 and 5 microns in diameter with a high surface area tomaximize interactions with immune cells. After absorption at the gutassociated lymphoid tissue (GALT) or following injection, thebeta-1,3-glucan particle is ingested and cleaved by macrophage cells.Macrophage cell size varies between species. For example, hamster andrat aveolar macrophage diameters average about 13.6 and 13.1 microns,respectively, with macrophages from monkeys averaging 15.3 microns andmacrophages from humans averaging 21.2 microns. The particle size of thebeta-1,3-glucan molecule should be the appropriate size to maximizeuptake at the GALT and also into the macrophages. The ideal particlesize may differ between species. Macrophage cells can vary in sizebetween different organisms, which may explain a portion of thevariability between optimal beta-1,3-glucan particle sizes.

The molecular weight of a beta glucan substance is known to affect theeffectiveness of the compound in immune stimulation applications.Beta-1,3-glucans produced by Euglenoids can typically have a molecularweight of about 200-500 kDa.

TABLE 3 Sources of Beta Glucans, Structures, and approximate MolecularWeights. Native Molecular Form Weight Name Source Solubility Structure(kDa) Glucan from Algae Particulate β-(1,3) unbranched 200-500Euglenoids Glucan from Yeast Particulate β-(1,3) β-(1,6) branched (30:1)200 Saccharomyces Curdlan Gram Particulate β-(1,3) unbranched  50-200negative bacteria Laminarin Brown Soluble β-(1,3) with some β-(1,6) 7.7seaweeds branching (30:1). The β-(1,6) side chains are composed of twoglucose units. Scleroglucan Fungus Soluble β-(1,3) β-(1,6) branched(6:1). 1020 The β-(1,6) side chains are composed of two glucose units.

Level of Purity of Beta-1,3-Glucan

The level of purity of a beta glucan compound has been determined tohave an effect on efficacy, possibly stemming from other materialpresent that inhibits the interaction between the beta glucan and immunecells. Using the methods described herein, paramylon can be easilyisolated in the form of granules from Euglenoid cells. As a result, thepurity of paramylon is very high relative to common preparations of betaglucans from yeast and other organisms. Using the methods describedherein, purity levels greater than 98% (measured by an enzymatic assaywhich detects beta glucan, Megazyme) can be obtained. In comparison, thehighest-grade yeast-derived beta glucans can rarely achieve greater than90% purity and several commercial products in the animal feed industryspecify only about a 35-60% purity. Moreover, achieving high puritybeta-1,3-glucan can be achieved more cost-effectively than withyeast-derived glucans due to the ease of separation resulting from thelack of a cell wall in Euglenoids and easy recovery of paramylongranules. Finally, since no harsh chemicals (e.g., strong acids andbases) are required to recover the paramylon granules, the beta glucancan be recovered in its native form without modifying its chemicalcomposition and configuration. In some cases, the use of pure,unmodified paramylon can be advantageous in comparison to solubilizedand modified paramylon or beta glucans obtained from other organismsthat are modified during the extraction process.

Method for Production of Paramylon in Euglena gracilis

Euglena sp. may be grown in a controlled environment, such that theEuglena remain the dominant microorganism in the environment. This isnot easy to achieve, as other organisms are typically capable ofcompeting for the same biological resources (e.g., nutrients,micronutrients, minerals, organic energy, and/or light), Many of thesemicroorganisms typically have a faster growth rate and are capable ofout-competing Euglena absent several controlled growth mechanisms thatfavor Euglena sp. These growth mechanisms can include one or moremethods such as employment of growth media that favors Euglena,operation at a temperature that favors Euglena, addition of acids andbases that favor Euglena, addition of compounds that are toxic tocompeting organisms other than Euglena, selective filtration orseparation of Euglena, and addition of micro-predators or viruses thatcontrol the populations of organisms that are not Euglena. All of thesemethods affect the growth rate and the ability of Euglena to convertenergy into beta glucan.

In order to achieve a sufficient population of the algae or protist, theorganism can also be grown in large aerobic fermentation vessels thatare similar to those vessels used to grow yeast. In some embodiments,these vessels may be non-pharmaceutical grade vessels used in thecommercial production of lysine, or other amino acids or proteins usingSaceharemyces sp., Eschericia coli, or other microorganisms.

The conversion of energy to bioavailable beta glucan may be enhanced bythe addition of an organic carbon source to the Euglena growth media, bythe selective addition of light, or by both. Again, these aspects affectthe ability of Euglena to compete with other organisms. In general,Euglena that are grown in an uncontrolled environment will not displaythe same beneficial properties of high beta glucan concentration, fastgrowth rates, and efficient production of beta glucans that Euglenaproduced in a more controlled growth environment will display.

The growth of high concentrations of beta glucan-containing Euglenareduces the cost of beta glucan production in several ways, includingthe following. First, the beta glucan containing compounds are notcontained in the cell wall of the organisms and do not require elaborateand/or expensive fractionation methods or extraction processes. Second,the Euglena organisms are relatively large and may be separated fromwater relatively quickly by employing a centrifuge, filter, or otherseparation device. Third, individual Euglena cells are composed of alarger percentage of beta glucan (as a percent of total cell mass) incomparison to other organisms, which results in high rates of conversionof organic sugars to beta glucan and easier recovery of the beta glucan.Fourth, aglow are capable of heterotrophic and photosyntheticmetabolisms, and therefore can convert free energy, in the form oflight, into valuable beta glucans. Fifth, beta glucans produced fromEuglena are not totally identical to other beta glucans. However, insome embodiments the Euglena derived beta glucans can be used incombination with other beta glucans (e.g., yeast derived beta glucans)in order to provide immune modulation properties.

Beta glucans from Euglena have not been studied as thoroughly as thosefrom yeast. The extent that Euglena derived beta glucans modulate theimmune system can be compared with yeast derived beta glucans.Experiments comparing Euglena derived beta glucans and yeast derivedbeta glucans are described in the Examples contained herein.

In their native state, yeast-derived glucans are present in lower puritycompositions and are also bound into the cell wall to other moleculesthat may have either a stimulatory or inhibitory effect. Yeast-derivedbeta glucans also contain 1,3;1,6 branching that is not present inEuglena-derived glucans. Because yeast-derived beta glucans requireextraction, it is likely that the extraction may result in additionalmodifications to the three-dimensional structure of the beta glucans,such as by cleaving portions of the beta glucans or by winding orunwinding helical coils or other structures.

Beta glucans from different sources can vary in terms of backbonestructure, branching linkages; frequency and length, molecular weight,and other features. Research presented at the National Cancer InstituteConference demonstrated that even slight variations in thesecharacteristics can affect bioactivity (see the online documentavailable at: www.immunehealthbasics.com/GlucaStructureNR.html). Forexample, in an in vivo anti-tumor study, beta-1,3;1,6-glucans from threeseparate sources with similar primmy structures were combined with amonoclonal antibody in a lymphoma model.

One form of beta-glucan that is commercially available is WellMune™(Biothera Corporation, Eagan, Minn.), which is derived from yeast.Another form ofbeta-glucan also produced using yeast is available fromBioTec Pharmacon (Norway), marketed as Macrogard by Immunocorp (Norway).

Extraction of Beta Glucans from Euglena gracilis

The beta glucan may be extracted from the algae or protist cell througha liquid-solid separation, a physical separation method, or anothermethod. The resulting purified beta glucan compound may undergoadditional reactions in order to improve the binding affinity, or toalter the binding affinity for a specific purpose. For example, sulfatedpolysaccharides have shown to be effective in treating HIV (Damonte,Elsa B, Matulewicz, Marfa C., Cerezo, Alberto S; Current MedialChemistry; 2004). Sulfated beta glucans from algae or protist sourcesmay demonstrate similar efficacy. Additional process that may be used toalter the structure of the beta glucan compound in order to increase oralter the efficacy of immune system stimulation are phospholylation,acetylation, and amination.

Method of Oral Administration

The beta glucans from Euglena may also be added to the diet of animalsfollowing isolation from the Euglena cells. Simple procedures to Iysethe Euglena cells and concentrate the beta glucan can achieve a productthat can exceed 75% purity of beta glucan. This isolated product has thebenefit of being more concentrated, having lower protein content toreduce allergic reactions, and also permits a longer shelf life. Thisisolated product can be incorporated into diets of animals in order toachieve a target beta glucan dosing, or in the case of variousaquaculture applications, the beta glucan can be added to the waterdirectly in the form of particles or feed pellets where it is ingestedby the target aquaculture species.

In some embodiments, the present technology can stimulate a macrophageresponse using Euglena derived beta glucans. Stimulation of themacrophage response is known to activate a cytokine pathway thatpromotes enhanced general immune system activity. Such a response may bedesirable for prevention of infections, treatment of tumors and cancers,or to support a compromised immune system, as would be expected in animmune deficiency syndrome, a patient undergoing surgery orchemotherapy, or a patient with severe burns. The beta glucans may beadministered orally, injected, using a nasal spray, or as a topicalointment or cream. The beta glucan may be administered continually orduring specific times when the immune system may be challenged, such aswhen an organism is young, is stressed, or is about to undergo surgeryor another operation. A period of stress may occur during a transfer toa new environment, inclusion in a larger or new population of organisms,or when an organism is about to undergo something that could bechallenging to its immune system.

Feed Compositions:

Feed compositions typically vary between species. Different feedcompositions are also given to the same species for different purposesand at different life stages.

Dosing:

The amount of beta glucan to be added as a feed supplement can rangebetween 0.001% to 2% of the total mass of the feed, as measured by dryweight analysis.

TABLE 4 Examples of Beta Glucan (BG) Dosing Percentages. Low PreferredHigh Perfect of feed (% of 0.01% 0.10% 1% daily feed that is BG) Dailyfood 0.50% 2.00% 5% consumption, as % of body mass Daily BG 0.00005%  0.00200%   0.0500%    consumption, as % of body mass

Exact dosing levels of algae or protist-derived beta glucans in ananimal food composition can depend on the beta glucan percentage andefficacy, the organism, and the dosing schedule.

One example of an animal feed application is to feed Euglena derivedbeta-glucan to swine. In this example, Euglena gracilis can be grownheterotrophically in a controlled environment (through the manipulationof carbon source, nutrient levels, pH, temperature, and other factors),centrifuged or filtered to remove it from the water, and dried. Theexact conditions of growth, as well as additional factors such aslighting and the addition or removal of molecules can affect theultimate beta glucan composition, structure, and relative abundance (bymass). The resulting algae meal can be mixed directly into an animalfood composition to be fed to the swine. The beta glucan supplement canbe incorporated into the feed composition and fed to the swine multipletimes per day, daily, or less frequently.

As described, Euglena gracilis that is grown heterotrophically can beadded to the animal feed composition for swine. When dosed properly andfed according to a proper schedule, this can have a beneficial on theanimal's overall well-being, as may be measured by increased survivalrates, increased growth rates, increased feed conversion efficiency.Alternatively, effects on the immune system may be measured directly bymeasuring indicating factors such as ADO, ADFI, G:F, the lymphocyteproliferation index, cytokine levels, cortisol levels, tumor necrosisfactor-alpha, or IL-10. In a controlled experiment, the addition ofalgae or protist meal containing active P-1,3 glucans may demonstratestatistically significant differences in one or more of these factorsbetween the control or experimental groups. Experiments illustratingsuch measurements are found in the Examples provided herein. Theaddition of Euglena gracilis to the animal food composition in thecorrect dosing levels can affect these biochemical indicators andprovide a beneficial effect on the well-being of the organism.

Other applications include adding the Euglena derived beta glucan to afeed composition that is fed to poultry, cows, fish, shrimp, horses,dogs, cats, reptiles, birds and other animals, including valuable orexotic animals kept at zoos or in aquariums.

Examples of ingredient combinations for selected applications:

When combined into animal feed, the Euglena derived beta glucan may becombined at a range of dosing levels, but generally this level can bebetween 1:10,000 and 1:500 by dry weight. Specific ingredientcombinations may differ between organisms, life stages, and the desiredoutcomes. Additionally, Euglena derived beta glucans can be combinedwith other immune-stimulating ingredients in order to provide themaximum immune stimulation benefits. Example ingredient combinations arelisted below for poultry, swine, and canine applications. Algae orprotist-derived may be combined with any combination of (but not limitedto) these ingredients in order to make an animal teed product.

There are many animal feed ingredients that may also benefit fromcombination with beta glucan. Common animal feed components, forexample, can include one or more of the following ingredients: cornmeal, dehulled soybean meal, wheat middlings, limestone,monocalcium-dicalcium phosphate, salt, manganous oxide, manganesesulfate, zinc oxide, ferrous sulfate, copper sulfate, cobalt carbonate,calcium iodate, sodium selenite, vitamin A, vitamin D, vitamin E,Menadioane sodium bisulfate complex (source of vitamin K complex),riboflavin supplement, niacin supplement, calcium pantothenate, vitamin1312, d-biotin, thiamine mononitrate, pyridoxine hydrochloride, folicacid, methionine, soybean oil, mineral oil, amino acids, Chicken,calcium, phosphoms, chrondrotin, glucosamine, Omega 3 & Omega 6, beetpulp, DHA (from fish oil), beta carotene, fish meal, Vitamin blend,alpha-linlenic acid, amino acids, arachidonic acid, ascorbic acid, beef,biotin, brewers yeast (dried), calcium carbonate, cellulose, chelatedminerals, chondroitin sulfate, cobalt, copper, corn meal, corn oil, dicalcium phosphate, DL-methionine, docosahexaenoic acid, dried eggproduct, durum flour, ethoxyquin, fat, carbohydrate, ferrous sulfate,fiber, fish meal, fish oil, flax meal, folic acid,frnctooligosaccharides, gelatin, glucosamine hydrochloride, glycerin,ground barley, ground corn, ground sorghum, guar gum, inositol, iodine,iron, Kangaroo, lamb, 1-carnitine, linoleic acid, lutein, magnesium,magnesium oxide, manganese, marigold extract, mannanoligosaccharid.es,minerals, mixed tocopherols, monosodium phosphate, niacin, marigold.extract, blueberries, dried kelp, phosphoms, potassium, potassiumchloride, potassium iodide, potassium sorbate, protein, pyridoxinehydrochloride, riboflavin, rice, rice flour, rosemary, rosemary extract,tapioca starch, taurine, thiamine mononitrate, titanium dioxide, vitaminA, vitamin B-1, vitamin B12, vitamin B-2, vitamin B-6, vitamin C,vitamin D3, vitamin E, vitamin K, water, wheat, wheat glutens, xanthangum, zinc, zinc oxide, zinc sulfate, any of the ingredients presentlylisted by the Association of American Feed Control Officials, andcombinations thereof.

Additional ingredients for enhancing immune system activity:

The following ingredients are related to enhanced immune systemperformance and can be combined with Euglena derived beta glucans ormeal in order to achieve the effects of enhanced immune system activity:vitamin C, alfalfa, flax seed, parsley, cranberries, spirulina,chlorella, vitamin A, vitamin E, copper, zinc, chromium, iron, arginine,alklyglcerol, coenzyme QIO, dimethglycine, phytonutrients, betacarotene, essential oils, fish oils, spices and their derivatives, andcombinations thereof.

The ingredients above may be used in various applications and forfeeding various organisms. For example, the ingredients listed herein asanimal feed components may also be combined with algae orprotist-derived beta glucans for dog, cat, poultry, aquaculture andother feed applications, In addition to the immune stimulation benefitsof Euglena derived beta glucans, the additional algae biomass may beincorporated. In particular, Euglena gracilis or another species may begrown such that relatively high concentrations of valuable DHA, Omega 3fatty acid, Omega 6 fatty acid, and tocopherols are also added to thefeed composition.

Additional Compositions

Although beta glucan can be beneficial when included with one or morefeed ingredients, there may be certain synergistic effects when betaglucan is fed in combination with one or more additional substances. Forexample, beta glucan may be fed in combination with probiotics such asBacillus licheniformis or Bacillus subtilis to provide a synergisticeffect. In this embodiment the up-regulation of the immune system mayhelp the body to naturally fight invasive pathogens while the probioticsmaintain a healthy intestinal flora that are more stable to overturn.Beta glucan that is fed in combination with other types ofnon-digestible fibers (e.g., prebiotics) may also exhibit a synergisticeffect. Examples of prebiotics that may be beneficially combined withbeta glucan include but are not limited to fructooligosacchaddes (FOS),lactulose and mannan oligosaccharides (MOS). Prebiotics combined withbeta glucan may be derived from yeast, micro-algae, grains, kelp, otherterrestrial plants, and other sources. Other substances that may bebeneficial in combination with beta glucan include vitamin C, vitamin E(specifically RRR alpha tocopherol), carotenoids (Astaxanthin,beta-carotene, lutein, zeaxanthin), DHA or EPA fatty acids, trace metals(iron, magnesium, lithium, zinc, copper, chromium, nickel, cobalt,vanadium, molybdenum, manganese, selenium, iodine), halquinol, MEDetoxizyme, vitamin D3, ascorbic acid, and dietary minerals (calcium,phosphorus, potassium, sulfur, sodium, chlorine, magnesium, boron,chromium). Beta glucan may also be fed in combination with otherenzymes, which may improve the bioavailability or digestibility of oneor more nutrient sources in the feed. In some cases, beta glucanase maybe provided as an enzyme in the feed to cleave the beta glucan intosmaller, more digestible fragments or to release the metal from a metalbeta glucan complex. In some embodiments, one or more of theseadditional substances can be included in the residual algae meal, whichmay be cultivated with the intent of increasing the concentration of thesynergistic substances.

Further ingredients can be combined with beta glucan and the variousbeta glucan compositions described herein. These include an additionalimmune modulating, stress reducing, or other stimulant ingredientselected from the group consisting of alpha tocopherol, cholecalciferol,zinc, chromium, selenium, arginine, ascorbic acid, alklygicerol,caffeine, kava kava, curcuma longa, spirulina, calcium D-glucarate,coenzyme Q10, peptides, dimethglycine, docosahexaenoic acid,ecosapentaenoic acid, alpha-lineolenic acid, astaxanthin, beta carotene,lutein, lactobacillus probiotics, bifidobacterium probiotics,mannoliggosaccharide, fmctooliggosacharides, Astragalus, Echinacea,Esberitox, garlic, glutathione, kelp, L-arginine, L-ornithine, lecithingranules, extracts from maiitake, reishi or shiitake mushrooms,manganese, quercetin, bromelain, Olive Leaf, Sambucus, Umcka,panthothenic acid, quercetin, alpha lipoic acid, essential oils, fishoils, spices and their derivatives, pterostilbene, and combinationsthereof.

Complexes with Trace Metals

In some embodiments, beta glucan can be complexed with a trace metal inorder to create a complex that simultaneously be used to improve tracemetal bioavailability while promoting general immune system activity.Trace metals include copper, zinc, iron, cobalt, magnesium, molybdenum,manganese, and combinations thereof. The beta glucan and trace metalcomplex can be the result of complexing a soluble, inorganic trace metalsalt with a beta glucan in solution.

The beta glucan polysaccharide can comprise either a bioavailable formof beta glucan, such as paramylon granules that are present in a dry orwet whole cell algae suspension or beta glucan present in a dry or wetwhole cell yeast, or an extracted source of beta glucan from algae,yeast, or another organism. The polysaccharide can be comprised of asuspension or paste of Euglena gracilis that has been grownheterotrophically in one or more sterile bioreactors. The Euglena canalso be grown in an optimal manner such that the beta glucan p01lion ofthe algae product comprises greatel than 20% of the algae biomass, asmeasured on a dry weight basis. Examples of processes for growing andcreating such products are illustrated in FIGS. 5 and 6,

With reference to FIG. 5, an embodiment of a fermentation process isshown. Algae biomass is produced in a fermenter (1) under sterileconditions on chemically defined media. After the desired amount of timein the fermenter (1), the fermenter broth is transferred to a centrifuge(2) that dewaters the broth to produce two process streams: a wet algaemeal that contains about 75% moisture; and used media. The wet algaemeal contains a mixture of whole algae cells, algae cell fragments, andpolysaccharides granules. The wet algae meal can be a polysaccharidesolution containing over 50% by dry weight of beta glucan, anon-digestible polysaccharide. The wet algae meal is transferred tomixer (3), such as a mixing tank or any piece of equipment capable ofmixing (e.g., ribbon blender). Optionally, the pH of the polysaccharidesolution can be adjusted by the addition of acid or base (A).

A concentrated solution of a soluble metal salt (B), such as ZnSO4-H2O,can be added to the mixer (3) and mixed vigorously with thepolysaccharide solution for 1-120 minutes. Any water soluble metal salt(B) may be used, For example, the metal salt (B) can be mixed with thebeta glucan so that the final product can be a copper polysaccharidecomplex, zinc polysaccharide complex, iron polysaccharide complex,cobalt polysaccharide complex, magnesium polysaccharide complex,manganese polysaccharide complex, and combinations thereof. Preparationof the soluble metal salt (B) solution may involve heating a mixture ofthe metal salt (B) in water with mixing. Optionally, this mixer (3) maybe heated or cooled. Optionally, the mixer (3) may be heated to thetemperature required to pasteurize the material and inactivate enzymeactivity. When the polysaccharide solution and metal salt (B) solutionare mixing, some amount of complexation will occur between the metalions and the polysaccharides present in the wet algae meal such that thefinal product may be considered a metal polysaccharide complex.

After the desired amount of mixing, the mixture is transferred to adehydrator (4), which is any device capable of drying the material. Forexample, the dehydrator (4) may be a tray dryer, belt dryer, rotary drumdryer, etc. Once the material contains less than 10% moisture, it istransferred to a mill (5) where its patlicle size is reduced to lessthan 500 μm. More preferably, its pailicle size is reduced to less than250 μm. Once the material has been milled, it is packaged (6) intocontainers of suitable size and labeled. Optionally, the addition of themetal salt (B) solution to the wet algae meal may be omitted and theresultant product will be algae meal.

With reference to FIG. 6, another embodiment of a fermentation processis shown. Algae biomass is produced in a fermenter (7) under sterileconditions on chemically defined media. Optionally, algal biomass may beproduced in a growth tank under non-sterile conditions using any mediathat contains only feed-grade materials and is free of harmfulsubstances (e.g., heavy metals, toxins, dangerous chemicals). After thedesired amount of time in the fermenter or growth tank (7), thefermenter broth is transferred to a mixer (8), such as a mixing tank orany piece of equipment capable of providing mixing (e.g., ribbonblender). The fermenter broth contains a mixture of whole algae cells,algae cell fragments, and polysaccharides granules. In the case of anon-sterile growth tank, low levels of non-algal biomass may also bepresent. Optionally, the pH of the fermenter broth is adjusted byaddition of acid or base chemicals (C) to the mixer (8) to lyse cells,thereby releasing the majority of the polysaccharide granules fromwithin the cells. This may be accomplished by adding base (e.g., NaOH)to the fermenter broth. Optionally, the broth may also be processedmechanically through a high-pressure homogenizer or ultrasonic celldisruptor to lyse cells. Optionally, the broth may be adjusted to analkaline pH and then neutralized prior to centrifugation. Aftersufficient time that most if not all cells are lysed, the resultantmixture is transferred to a centrifuge (9) that dewaters the broth toproduce two process streams: a crude polysaccharide solution (D); andmixture of other biomass materials (E).

The crude polysaccharide solution (D) is transferred to a mixer (10),such as a mixing tank or any piece of equipment capable of providingmixing (e.g., ribbon blender). The crude polysaccharide solution mayoptionally be washed with water or a suitable alcohol (ethanol,isopropanol) to remove non-polysaccharide materials. Additional washesmay be performed with any chemical suitable to remove non-polysaccharidematerials. The pH of the crude polysaccharide solution (D) mayoptionally be adjusted with acid or base (F).

A concentrated solution of a soluble metal salt (G), such as ZnSO4-H2O,is prepared and added to the mixing tank (10) and mixed vigorously withthe polysaccharide solution for 1-120 minutes. Any water-soluble metalsalt may be used, such that the final product can be, for example, acopper polysaccharide complex, zinc polysaccharide complex, ironpolysaccharide complex, cobalt polysaccharide complex, magnesiumpolysaccharide complex or manganese polysaccharide complex. Preparationof the soluble metal salt solution may involve heating a mixture of themetal salt in water with mixing. Optionally, mixer (10) may be heated orcooled. Optionally, the mixer (10) may be heated to the temperaturerequired to pasteurize the material and inactivate enzyme activity. Whenthe polysaccharide solution and metal salt solution are mixing, someamount of complexation will occur between the metal ions and thepolysaccharides present such that the final product may be considered ametal polysaccharide complex.

After the desired amount of mixing, the mixture is transferred to adehydrator (11), which is any device capable of drying the material. Forexample, the dehydrator (11) may be a tray dryer, belt dryer, rotarydrum drier, etc. Once the material contains less than 10% moisture, itis transferred to a mill (12) where its particle size is reduced to lessthan 500 μm. More preferably, its particle size is reduced to less than250 μm. One the material has been milled, it is packaged (13) into bagsof suitable size and labeled.

The non-polysaccharide material (E) contains partially hydrolyzedproteins and amino acids and is transferred to a mixer (14), such asmixing tank or any piece of equipment capable of providing mixing (e.g.,ribbon blender). The pH of the non-polysaccharide material (E) mayoptionally be adjusted with acid or base (H), A concentrated solution ofa soluble metal salt (I), such as ZnSO4-H2O is prepared and added to themixer (14) and mixed vigorously with the amino acid-rich material for1-120 minutes. Any water-soluble metal salt may be used, such that thefinal product can be, for example, a copper proteinate, zinc proteinate,iron proteinate, cobalt proteinate, magnesium proteinate, manganeseproteinate, and combinations thereof. Preparation of the soluble metalsalt solution may involve heating a mixture of the metal salt in waterwith mixing. Optionally, mixer (14) may be heated or cooled. Optionally,the mixer (14) may be heated to the temperature required to pasteurizethe material and inactivate enzyme activity. When the non-polysaccharidesolution and metal salt solution are mixing, some amount of complexationwill occur between the metal ions and the partially hydrolyzed proteinsand amino acids present such that the final product may be considered ametal proteinate.

After the desired amount of mixing, the mixture is transferred to adehydrator (15), which is any device capable of drying the material. Forexample, the dehydrator (15) may be a tray dryer, belt dryer, rotarydrum drier, multi-effect evaporator, etc. Once the material containsless than 10% moisture, it is transferred to a mill (16) where itsparticle size is reduced to less than 500 μm. More preferably, itsparticle size is reduced to less than 250 μm. Once the material has beenmilled, it is packaged (17) into bags of suitable size and labeled.Optionally, the addition of the metal salt solution to each processstream (D, E) may be omitted and the resultant products will be arelatively pure polysaccharide and partially hydrolyzed protein meal.

Advantages to complexing the trace metal and the beta glucan include anincrease in the bioavailability of the trace metal in combination withthe immune system modulating aspects of beta glucan. The beta glucan isindigestible in the gut and can shield the trace metal from binding toan agonist until it is released in the intestine, for example.Furthermore, because some trace elements, such as zinc, are typicallyrequired in the diet in order to obtain optimal immune systemfunctionality, the combination with an immune enhancing compound such asbeta glucan can be more preferable in some situations for combining intoan animal feed or vitamin premix blend than combining the same tracemetal with another source, such as an amino acid or protein, which canalso be provided as a separate product. The present processesdemonstrate the capability of Euglena-derived beta glucan to bind orabsorb large enough concentrations of zinc and other trace metals todeliver significant concentrations of the trace metal in an animal diet.

Some embodiments of a metal beta glucan complex include a memberselected from the group consisting of a copper beta glucan complex, zincbeta glucan complex, iron beta glucan complex, cobalt beta glucancomplex, magnesium beta glucan complex, molybdenum beta glucan complex,manganese beta glucan complex, and combinations thereof.

Although any trace-mineral containing inorganic salt may be used, someexamples of salts include those that are commodities already usedcommercially as feed ingredients. Examples of such inorganic saltsinclude but are not limited to metal sulfates, metal oxides, metalchlorides, hydrated metal salts, metal acetates, metal bromides, metaliodides, metal phosphates, metal selenites, and combinations thereof,where a pot lion of the salt can include iron, magnesium, lithium, zinc,copper, chromium, nickel, cobalt, vanadium, molybdenum, manganese,selenium, tungsten, iodine, and combinations thereof.

In some embodiments, the resulting metal polysaccharide complex includes3% to 25% by weight metal and at least 25% by weight beta glucan. Incertain cases, the polysaccharide portion of the product can becomprised of at least 50% by weight beta glucan. Zinc sulfate or zincoxide may be used as the trace mineral-containing salt to make a zincbeta glucan complex, where the zinc beta glucan complex can comprise atleast 1% by weight zinc on a dry weight basis that can be administeredat less than 3% by weight total inclusion in an animal's diet.

Measuring the Effects of Beta Glucan

The animal feed composition described herein is expected to generallymodulate the immune system. Ultimately, such benefits can translate intoimproved general well-being and health in animals, and improvedeconomics of livestock production, especially in livestock productionmethods that do not employ a sub-therapeutic use of antibiotics in thewater or in animal feed. Methods to evaluate use of the presentcompositions in animal teed include measuring increases in antibodytiters, measuring increases in the activity of immune system cells(e.g., rates of phagocytosis and natural killer cell cytotoxicity),measuring improvements in feed conversion efficiency, measuringdecreased stress, measuring improved weight loss or weight gain,measuring improvements in feed consumption, measuring improvements inaverage daily gain, performing challenge studies where at least one ofthe treatment groups is administered a composition as described herein,measuring reduced mortality rates in an animal population, measuringalternations in levels of interleukins or other cytokines which areknown to be related to immunological performance, measuring effects ontumor necrosis factor alpha, fluorescently tagging components of thecompositions described herein and observing their presence or metabolismin various cell, blood, or tissue samples, performing generalhistological analysis on animals that are fed a composition describedherein, weighing the organs or animals which are fed a compositiondescribed herein, or any other analysis that demonstrates a significanteffect on animals when they are fed one or more of the compositionsdescribed herein.

Animal Feed Milk Replacer

The present animal feed compositions can be formulated as a milkreplacer, where a milk replacer is a product that is fed to a youngmammal as a supplement, or a replacement for the mother's natural milk.Milk replacer products exist for a wide range of mammals, including butnot limited to cows, goats, lambs, sheep, squirrels, humans, and evenexotic zoo animals. Some mammals, such as cows, have a ruminantdigestive system. However, young ruminants do not have fully developedor functional digestive systems-organs that produce digestive enzymesare not fully functional at birth. These young ruminants suffer fromvariations in diet, and are particularly vulnerable to infection andstress. Milk replacer comprising crude protein, crude fat, whey, andother substances is often provided to young cows in order to reducevariability in their diet and also because it can be more economic tofeed them milk replacer and to sell the mother's milk.

Milk replacers usually contain some combination of components of thefollowing substances: whey protein, fat, crude protein, emulsifier, flowagent, dicalcium phosphate, lysine, vitamins, trace minerals, calciumcarbonate, choline, flavor compounds, ash, calcium and phosphate.Sources of fats and proteins can be animal or plant-based. Different fatcompositions, as measured by hydrocarbon chain length, and proteincomposition, as measured by amino acid components, have been shown toyield different outcomes in terms of feed conversion efficiency, weightgain, growth rates, mortality, and overall resistance to infections.

The present technology includes an animal feed composition that isformulated as a milk replacer, where the milk replacer can includeprotein, fat, and beta glucan in order to provide substantive caloriesand to enhance the well-being of a mammal. Also included is a method ofstimulating an increase in body weight and for enhancing the well-beingof a young mammal by feeding it a milk replacer product comprising ofprotein, fat and beta glucan.

EXAMPLES

Beta Glucan Branching Analysis

A branching analysis was performed on beta glucan extracted from Euglenagracilis grown using a heterotrophic, sterile fermentation approach.

The following methods were employed.

Cell culture and beta glucan measurements. Two cultures of Euglena wereeach grown on a media containing major and minor essential nutrients(including nitrogen, phosphorus), trace minerals, and vitamins (B1 andB12) as is common for the growth of this species. The 200 ml cultureswere bubbled with air in 250 ml Erlenmeyer flasks to provide oxygen,carbon dioxide, and mixing of the cultures. Initial Euglena density was0.7 g L″1·Both cultures were exposed to light levels of 150 μmol photonm s·1 and 4 g L″1 of fixed carbon was dosed as a supplemental carbontreatment to one culture. After two days, the samples were measured fortotal suspended solids to determine the dry weight of the biomass. Betaglucan content was determined by lysing the cells and centriffiging thebeta glucan crystals. Approximately 1 part Euglena biomass (dry weightbasis) is suspended in 5 pails water and 10 patis of (10 g/L sodiumdodecyl sulfate). This solution mixed vigorously and then heated to 100deg C. for 30 minutes. The solution is then cooled and centrifugedat >500 g for 5 minutes. The supernatant is discarded and the pellet iswashed by re-suspension in 10 patis water, mixed vigorously andcentrifuged at >500 g for 5 minutes. The washing process is repeated 2more times with 10 patis of 70-95% ethanol, to arrive at a purified betaglucan pellet. The pellet can further be dried to a white/tan powderunder a vacuum at 65 deg C. FIG. 7 shows the mass in dry weight perliter of Euglena and beta glucan grown in the control media and a mediahaving the supplement carbon treatment. FIG. 8 shows the percent betaglucan by dry weight of Euglena grown in control media and the mediahaving the supplemental carbon treatment.

Per-O-methylation and linkage analysis. For glycosyl linkage analysis,two samples of beta glucan extracted using the methods above, werepermethylated, depolymerized, reduced, and acetylated; the resultingpartially methylated alditol acetates (PMAAs) were analyzed by gaschromatography-mass spectrometry (GC-MS) as described by York et al(1985) Methods Enzymol. 118:3-40.

Initially, dry sample was suspended in about 300 μl of dimethylsulfoxide and placed on a magnetic stirrer for 1-2 weeks. The sample wasthen permethylated by the method of Ciukanu and Kerek (1984) Carbohydr.Res. 131:209-217 (treatment with sodium hydroxide and methyl iodide indry DMSO). The sample was subjected to the NaOH base for 10 minutes thenmethyl iodide was added and left for 40 minutes. The base was then addedfor 10 minutes and finally more methyl iodide was added for 40 minutes.This addition of more methyl iodide and NaOH base was to insure completemethylation of the polymer. Following sample workup, the permethylatedmaterial was hydrolyzed using 2 M trifluoroacetic acid (2 h in sealedtube at 121° C.), reduced with NaBD4, and acetylated using aceticanhydride/trifluoroacetic acid. The resulting PMAAs were analyzed on aHewlett Packard 5975C GC interfaced to a 7890A MSD (mass selectivedetector, electron impact ionization mode); separation was performed ona 30 m Supelco 2330 bonded phase fused silica capillary column,

TABLE 5 Result of Per-O-Methylation and Linkage Analysis from 2Extracted Beta Glucan Samples. Sample β-glucan 1 β-glucan 2 glycosylresidue PKaren % terminally-linked glucopyranosyl residue (t-glc) 0.340.3 3-linked glucopyranosyl residue (3-glc) 93.03 94.1 4-linkedglucopyranosyl residue (4-glc) 2.25 2.4 2,3-linked glucopyranosylresidue (2,3-glc) 3.47 2.3 3,6-linked glucopyranosyl residue (3,6-glc)0.36 0.8 2,3,4-linked glucopyranosyl residue (2,3,4-glc) 0.55 0.1 Total100.0 100.0

Linkage results indicate that both samples are mainly composed of3-linked glucopyranosyl residues. Minor amounts of 4- and 2,3-linked Glcresidues are detected along with negligible amount of 3,6-linked,terminal and 2,3,4-linked Ole.

Immune Response Parameters in Mice

A study was conducted in collaboration with Dr. Vaclav Vetvicka in theDepartment of Pathology at the University of Louisville in order todetermine if paramylon was an effective immune stimulant in mammals whenprovided as a feed ingredient. Objectives included:

-   -   1. Determining whether paramylon stimulated the immune system of        mice when dosed orally;    -   2. Comparing the effects of paramylon vs. other beta glucan        products used in animal feed supplements at various dosage        levels; and    -   3. Evaluating the effectiveness of whole cell paramylon vs.        extracted and purified paramylon,

The following methods were employed.

Algal biomass containing beta glucan was grown using fermentationprocesses as described herein. Two different whole cell products (WBG50Aand WBG50B) and one purified beta glucan extract were tested in thismouse study. The WBG50A sample was produced from cells grown on glucoseas the organic carbon source, whereas the WBG50B sample was producedfrom cells grown on ethanol. Both whole cell products contained about 50wt. % beta-1,3 glucan and were centrifuged and then dried without anyfurther processing. Fractionating the WBG50A biomass to isolate the betaglucan and then repeatedly washing the beta glucan fraction to removenon-beta glucan cell components produced the “extract” sample. Theextract contained about 93 wt. % beta-1,3 glucan.

The whole cell biomass samples, beta glucan extract, and other betaglucan products were all dried and ground to particle sizes of less than500 microns. These dry powders were then mixed with PBS buffer anddiluted to appropriate concentrations before being dosed by gavage tothe mice. Three BALB/c mice were allocated to each treatment group andgiven varying levels of beta glucan on a weight percent of their totaldiet basis, ranging from less than 0.001% to 0.25% of the mouse dietration on day I of the experiment. Only the data from the 0.005% and0.05% dosing levels are represented here.

Blood was taken from each mouse to measure non-specific immune systemactivity. The following parameters were assessed: phagocytosis activity(the ability of macrophages to ingest foreign pa11ides), natural killer(NK) cell activity (the ability of NK cells to destroy foreign orinfected cells), and cytokine concentrations (IL-2). To measure thecapacity of the specific immune response, antibody formation in responseto ovalbumin was measured via enzyme-linked immunosorbent assay (ELISA)using a Freund adjuvant as a positive control and PBS as the negativecontrol.

The following results were obtained.

Phagocytosis is one response by the immune system to capture and destroypotentially harmful particles (e.g., bacteria). The phagocytosis indexwas measured as the percent of neutrophils that actively captured andengulfed labeled particles. Mice that were given only the PBS controlhad a phagocytosis index of30% (see FIG. 9). The highest recorded index(45%) was observed for mice fed the 0.05% dose of WBGS0B, which is a 50%increase over the control treatment. Overall, the WBG50B treatment hadthe highest phagocytosis index of all the treatments at each of the twodosage levels, and was especially effective compared to all of thetreatments at the lowest dosage level (0.005% of diet).

NK Cell Activity is an index of the ability for isolated natural killer(NK) cells from the spleen to kill target cells (e.g., YAC-1 cells froma T-lymphoma cell line) during a 4-hour incubation. Mice that were fedthe PBS control displayed a cytoxicity index of 12%, while the mice fedthe 0.05% dose of WBGS0B had a cytotoxicity index over three timeshigher (38.5%, see FIG. 10). Both the WBGS0B and the extract treatmentssubstantially outperformed other beta glucan products (Fibosel,Biomatrix) at both dosage levels, and in some cases, the WBGS0Btreatment showed nearly twice the NK cell activity response, asreflected by cytotoxicity, of Fibosel at the 0.05% and 0.005% dosagelevels.

Interleukin-2 (IL-2) is an imp011ant cytokine-messaging molecule thathelps regulate the immune response to microbial infection. IL-2production is measured as the amount of IL-2 produced by harvestedspleen cells during an incubation period. IL-2 response is a moregeneralized immune response than NK cell activity, phagocytosis, andantibody formation. As such, many different types of foreign compounds,not just beta glucan, can elicit an increase in IL-2 production. Micethat were fed the PBS control did not observe an increase in IL-2production, while all of the beta glucan product treatments elicited avery strong IL-2 response that was noticeably increased at the higherdosage rate (see FIG. 11). The extract treatment resulted in the highestIL-2 production, followed by the other beta glucan products (Fibosel,Biomatrix), and then the WBG50 products.

Antibody formation indicates that beta glucan can act as an adjuvant(enhancer) for vaccines. Mice were injected with ovalbumin (egg whiteprotein, a model antigen) on day 0 and day 14 while being fed each betaglucan product daily for 21 days. On day 21, the number of antibodies toovalbumin are measured in the serum. Freund adjuvant (an emulsion ofinactivated bacteria cells) was used as a positive control as it isrecognized as an industry standard for inducing antibody formation.However, Freund adjuvant is not used in many animals including humansbecause of its strong toxicity effect. As expected, the Freund adjuvantproduced a very high level of antibodies (see FIG. 12). At the 0.05%dosage rate, both whole cell samples and the competing products eachelicited similar antibody production at about 20% the level of theFreund adjuvant. The extract sample produced a much stronger antibodyresponse for the 0.05% dosage rate, reaching nearly 55% of the levelinduced by the Freund adjuvant.

These experiments establish the following precepts with respect to thepresent technology:

-   -   1. Each of the Euglena beta glucan containing products (WBG50A,        WBG50B, Extract) induced significant increases in each of the        immune responses measured (phagocytosis, NK cell activity, IL-2        production, antibody production) compared to controls.    -   2. For each measure of immune response, the Euglena beta glucan        products performed as well, and in many cases, better than the        other beta glucan products Fibosel and Biomatrix. In particular,        WBG50B (whole cell biomass grown on ethanol as the carbon        source), demonstrated the highest measured levels for        phagocytosis and NK cell activity.    -   3. The extracted Euglena beta glucan product elicited a very        strong antibody response that exceeded 50% of the level induced        by a Freund adjuvant, indicating the potential for adjuvant        applications.    -   4. With the exception of antibody production, the immune        response to whole cell biomass was as high, if not higher, than        the extracted Euglena beta glucan alone. This suggests that        other components of the algae cells (e.g., omega-3 fatty acids,        vitamin E, trace metals) can have a synergistic effect with the        beta glucan to induce a stronger immune response.    -   5. In all cases, the immune response to the dosage levels        (0.005% and 0.05%) was not linear (i.e., 10× higher) and        differed among products, suggesting that the optimal dosage rate        for the Euglena beta glucan products is likely much lower than        the highest dosage level (0.05%). Notably, the immune response        in NK cell activity and phagocytosis for the lowest dosage of        WBG50B was even higher than the for highest dosage level for        Fibosel and Biomatrix, suggesting the possibility for reduced        dosing requirements for Euglena beta glucan. Additionally,        dosage rates can be optimized for the phagocytosis response        which is the first line of defense against pathogens.

Efficient Production of Beta Glucan using Heterotrophic Fermentation ofEuglena gracilis

In order to determine optimal production of beta glucan with othersynergistic co-products using Euglena gracilis, a wide range differentgrowth media formulations, pH, temperature controls, light conditions,and genetic strains of Euglena were tested. Unexpectedly, it wasdetermined that Euglena gracilis produced greater quantities of valuableproteins and antioxidant lipids when grown in photosynthetic conditions.However, Euglena that was grown heterotrophically in dark, sterilefermentation vessels produced greater quantities of beta-1,3-glucan.Mice that were fed dried Euglena gracilis derived from sterilefermentation vessels showed immune system performance that exceeded betaglucans derived from yeast sources, or from Euglena that containedsmaller quantities of beta glucans.

Unlike other reports that describe production of vitamin E and otherantioxidants using algae grown photosynthetically, Euglena gracilisgrown heterotrophically appears to produce beta glucan that is bettersuited for animal feed applications.

Furthermore, the present experiments determined that it is important toquickly dry the algae as part of the manufacturing process in order toprevent the breakdown of valuable carotenoids and other antioxidants. Itshould be noted that in some cases it can be economically beneficial tostore a wet algae slurry for an extended period of time before drying.In one embodiment, freshly centrifuged algae can be preserved by heatingthe material in glass jars or retort pouches, similar to how food stuffsare canned for long term storage at room temperature. This informationwas used in developing the manufacturing processes described herein andillustrated in FIGS. 5 and 6.

TABLE 6 Examples of Compound Concentrations in Euglena Samples (dryweight basis) Concentration in wet Concentration in sample sample storedat room dried immediately temperature for 2 days after centrifugingLutein 80 ppm 145.7 ppm Zeaxnthin 17.2 ppm 2.9 ppm Astaxanthin 7.4 ppm7.6 ppm Beta-carotene 9.4 ppm 59.3 ppm DHA No data 0.33% EPA No data0.33% Alpha 126 IU/kg 34 IU/kg tocopherol

E. coli Challenge in Mice

Objectives of this example include:

-   -   1. Determining whether oral doses of Euglena algae meal and        purified beta glucan products increase survival against a lethal        dose of the bacterium Escherichia coli (E. coli);    -   2. Determining whether Euglena algae meal and beta glucan        products specifically stimulated the immune system of mice as        measured by antibody production, NK killer cell cytotoxicity,        and phagocytosis activity; and    -   3. Comparing the effects of Euglena algae meal and purified beta        glucan products to a other beta glucan products derived from        yeast at varying dosage levels.

The following methods were employed.

Euglena cells were grown in a sterile fermenter. Once the target densityof biomass was reached in the fermenter the cells were centrifuged andthe resulting paste was stored frozen at −20° C. To produce the algaemeal sample, the frozen paste was thawed, dried at 65° C. until itformed a dry flake, and then ground to a particle size of less than 250microns. The purified algae beta glucan sample was produced byfractionating the Euglena cells and isolating the beta glucan through aproprietary purification process that results in an extract with >90%beta glucan and a particle size of less than 250 microns. An extracted,yeast-derived beta glucan product, Macrogard, which guarantees >60% betaglucan, was procured from a commercial distributer and used “as-is”without further modifications. Each dry product was mixed with phosphatebuffered saline (PBS) and diluted to appropriate concentrations beforebeing dosed by gavage to the mice at prescribed dosing levels.

All animal work was conducted in the laboratory of Dr. Vaclav Vetvickain the Department of Pathology at the University of Louisville. Dr.Vetvicka is well known for his research on the physiological effects ofbeta glucan and his lab has conducted numerous side-by-side comparisonsof beta glucan products to determine their potential effectiveness.

E. coli Bacteria. Challenge, Ten BALB/c mice were allocated to eachtreatment group and received a nominal lethal dose of E. coli (3×107)via intramuscular injection on day 0. Beta glucan products (0.01% of thedaily feed ration by weight) were orally dosed by gavage to the micedaily starting two days prior to the injection (day −2) through two daysfollowing the injection (day +2). The control group received only a PBSgavage, while an antibiotic-treated group received oral doses ofAmpicillin (13 mg/kg) on days 0, 1, 2, 3 and 4, Mice were evaluateddaily up through day 10.

Antibody Titers. Three BALB/c mice were allocated to each treatmentgroup and received daily oral dose of beta glucan products equivalent to0.002, 0.005, 0.010 and 0.020% of their daily feed ration by weightstarting on day 0. The antigen (ovalbumin) was given by intraperitonealinjection on days 3 and 16 and antibody titer production was measured onday 23 using an ELISA assay with a Freund adjuvant as a positive controland PBS as the negative control.

NK Cell Cytotoxicity and Phagocytosis Activity. Nine BALB/c mice wereallocated to each treatment group and fed beta glucan products in thesame manner as the antibody titer experiment explained above in order tomeasure natural killer (NK) cell cytotoxicity (the ability of NK cellsto destroy foreign or infected cells) and phagocytosis activity (theability of macrophages to ingest foreign particles), On days 1, 7, and14, three mice from each treatment group were sacrificed to harvestmaterial for analyses. NK cell activity (measured as cytotoxicity) is anindex of the ability for isolated NK cells from the spleen to killtarget cells (e.g., YAC-1 cells from a T-lymphoma cell line) during a 4hour incubation. The phagocytosis index is measured as the percent ofneutrophil cells that actively capture and engulf labeled particles inan allotted time.

These experiments produced the following results.

E. coli Bacteria Challenge (see FIG. 13). All mice in the control group,which received only PBS, died within seven days of the E. coliinjection. In contrast, mortality at day 10 was decreased in alltreatment groups by at least 40%. Notably, 70% of the mice receiving thepurified algae beta glucan product survived 10 days following E. coliinjection. This treatment group and the one receiving Ampicillin showedvery similar survival rates over time, suggesting that theEuglena-derived beta glucan treatment promoted similar antibacterialactivity to Ampicillin. Mice receiving algae meal, which contains about50% beta glucan, also showed a significant decline in mortality comparedto the control group. In this treatment group, 50% of the mice survived10 days following E. coli injection compared to 40% surviving in thegroup fed a yeast-derived beta glucan extract product (Macrogard).

Antibody Titers (see FIG. 14). A significant increase in antibody titerindicates the potential for a product like beta glucan to serve as anadjuvant (enhancer) to vaccines. As expected, the positive control(Freund adjuvant, an emulsion of inactivated bacteria cells) producedvery high levels of antibodies to ovalbumin, However, Freund adjuvant istoxic and is not actually used in animals or humans as an adjuvant. Allof the beta glucan treatment groups elicited an increase in antibodyproduction that also increased with dosage rate. The purified algae betaglucan treatment produced the most antibodies at each of the treatmentdosage levels followed closely by the algae meal treatment group. TheMacrogard yeast beta glucan extract treatment group demonstratedsubstantially lower (between 15% and 50% lower) antibody titers than thepurified algae beta glucan and algae meal treatments at moderate dosinglevels (0.005 and 0.010%) but matched the algae meal treatment at thehighest dosage rate.

NK Cell Cytotoxicity (see FIG. 15). NK cell cytoxicity is an index ofthe non-specific immune response by NK cells to kill potentiallypathogenic organisms. Mice that were fed the PBS control displayed acytoxicity index of 12%, while the mice fed with doses as low as 0.005%of either the algae meal or purified algae beta glucan demonstrated acytotoxicity index over three times higher (36% to 50%). At doses of0.005% and higher, both the algae meal and purified algae beta glucantreatments elicited a stronger cytotoxicity response than the Macrogardyeast beta glucan extract treatments.

Phagocytosis Activity (see FIG. 16). Phagocytosis is anothernon-specific immune response to engulf potentially pathogenic organisms.Mice that were given only the PBS control had a phagocytosis index of30% while mice fed the highest dose of the purified algae beta glucandemonstrated nearly twice the phagocytosis activity (59%). As seen withthe NK cell cytotoxicity and antibody titers, the purified algae betaglucan treatment group demonstrated the best performance at each dosagelevel. The algae meal and. Macrogard yeast beta glucan extract treatmentgroups demonstrated similar phagocytosis activity at the two lowestdosage levels, but mice fed Macrogard yeast beta glucan extract at thetwo highest dosage levels had slightly higher phagocytosis activity.

Accordingly, the data from these experiments demonstrate the following:

-   -   1. Each of the beta glucan products (algae meal, purified algae        beta glucan, and Macrogard yeast beta glucan extract) increased        the survivorship of mice exposed to a lethal dose of E. coli. In        particular, the algae meal treatment increased survivorship at        day 10 from 0% in the control group up to 50%. The purified        algae beta glucan treatment increased survivorship up to 70%,        which was the same response as the antibiotic treatment        (Ampicillin). These data indicate that Euglena-derived beta        glucan stimulates the immune system to provide potent        antibacterial activity and that beta glucan within the algae        meal, which has not been extracted and pwified, is readily        bioavailable.    -   2. Both specific immune responses (i.e., antibody production)        and non-specific immune responses (i.e., NK cell cytotoxicity        and phagocytosis activity) increased significantly for treatment        groups fed any of the beta glucan products. For all of the        immune metrics, the purified algae beta glucan treatment group        elicited the strongest immune response at all treatment levels.    -   3. Both algae meal and purified algae beta glucan products        elicited a very strong antibody response that exceeded 50% of        the level induced by a Freund adjuvant, indicating the utility        of these products to serve as adjuvants.    -   4. Algae meal product performed as well, if not better, than the        Macrogard yeast beta glucan extract product at nearly all        treatment levels in both antibody production and NK cell        cytotoxicity assays. In most cases, the algae meal product        induced nearly the same or better response compared to Macrogard        at only one-quarter to one-half the dosage level.    -   5. Macrogard yeast beta glucan extract elicited a lower        phagocytosis response than the purified algae beta glucan        product, but performed as well or better than the algae meal        product. In general, the overall impact of all beta glucan        products on phagocytosis is more tempered than the effects on NK        cell cytotoxicity and antibody production.    -   6. These results corroborate earlier, shorter-duration (3 days)        studies that found algae meal and purified algae beta glucan        products to induce the enhanced immune responses compared to        controls and other yeast beta glucan products, such as Fibosel        yeast beta glucan extract and another generic yeast beta glucan        product.    -   Example embodiments are provided so that this disclosure will be        thorough, and will fully convey the scope to those who are        skilled in the art. Numerous specific details are set f01th such        as examples of specific components, devices, and methods, to        provide a thorough understanding of embodiments of the present        disclosure. It will be apparent to those skilled in the art that        specific details need not be employed, that example embodiments        may be embodied in many different forms, and that neither should        be construed to limit the scope of the disclosure. In some        example embodiments, well-known processes, well-known device        structures, and well-known technologies are not described in        detail. Equivalent changes, modifications and variations of some        embodiments, materials, compositions and methods can be made        within the scope of the present technology, with substantially        similar results

What is claimed is:
 1. A method of stimulating an immune response in ananimal, the method comprising feeding to the animal a compositioncomprising (i) heterotrophically grown Euglena comprising greater than20 weight % beta-(1,3)-glucan, wherein the Euglena is grown andfermented in a fermenter under sterile conditions and dried to containless than 10% moisture, and (ii) an animal feed component, wherein thebeta-(1,3)-glucan is present in an amount from 0.001% to 0.020% of thetotal weight of the animal feed.
 2. The method of claim 1, wherein thebeta glucan consists essentially of unbranched beta-(1,3)-glucan.
 3. Themethod of claim 1, wherein the beta glucan comprises greater than about90% unbranched beta-(1,3)-glucan.
 4. The method of claim 1, wherein thebeta glucan comprises paramylon.
 5. The method of claim 1, wherein theadministering comprises adding the composition to the animal's diet. 6.The method of claim 1, wherein the animal feed component comprises amember selected from the group consisting of astaxanthin, lutein,beta-carotene, eicosapentaenoic acid, docosahexaenoic acid, omega 3fatty acid, omega 6 fatty acid, alpha tocopherol, and combinationsthereof.
 7. The method of claim 1, wherein the beta-(1,3)-glucan isseparated from other Euglena components.
 8. The method of claim 1,wherein the average particle size of the Euglena is reduced to less than500 μm.
 9. A method of stimulating an immune response in an animal, themethod comprising feeding to the animal a composition comprising (i)heterotrophically grown Euglena comprising greater than 20 weight %beta-(1,3)-glucan, wherein the Euglena is grown and fermented in afermenter under sterile conditions and dried to contain less than 10%moisture, and (ii) an animal feed component, wherein thebeta-(1,3)-glucan is at about 10 ppm to about 200 ppm in the animalfeed, said beta glucan comprising greater than about 90% unbranchedbeta-(1,3)-glucan.
 10. The method of claim 9, wherein the beta glucanconsists essentially of unbranched beta-(1,3)-glucan.
 11. The method ofclaim 9, wherein the beta glucan comprises paramylon.
 12. The method ofclaim 9, wherein the administering comprises adding the composition tothe animal's diet.
 13. The method of claim 9, wherein the animal feedcomponent comprises a member selected from the group consisting ofastaxanthin, lutein, beta-carotene, eicosapentaenoic acid,docosahexaenoic acid, omega 3 fatty acid, omega 6 fatty acid, alphatocopherol, and combinations thereof.
 14. The method of claim 9, whereinthe composition comprises an additional immune modulating, stressreducing, or other stimulant ingredient selected from the groupconsisting of alpha tocopherol, cholecalciferol, zinc, chromium,selenium, arginine, ascorbic acid, alklyglcerol, caffeine, kava kava,curcuma longa, spirulina, calcium D-glucarate, coenzyme Q10, peptides,dimethglycine, docosahexaenoic acid, ecosapentaenoic acid,alpha-lineolenic acid, astaxanthin, beta carotene, lutein, lactobacillusprobiotics, bifidobacterium probiotics, mannoliggosaccharide,fructooliggosacharides, Astragalus, Echinacea, Esberitox, garlic,glutathione, kelp, L-arginine, L-ornithine, lecithin granules, extractsfrom maiitake, reishi or shiitake mushrooms, manganese, quercetin,bromelain, Olive Leaf, Sambucus, Umcka, panthothenic acid, quercetin,alpha lipoic acid, essential oils, fish oils, spices and theirderivatives, pterostilbene, and combinations thereof.
 15. The method ofclaim 9, wherein the beta-(1,3)-glucan is separated from other Euglenacomponents.
 16. The method of claim 9, wherein the average particle sizeof the Euglena is reduced to less than 500 μm.